NOAA National Weather Service Weather Forecast Office

Beginning of hail storm across far southern Wisconsin

Take a look at an animated radar image of the hail storms from 9:41 PM October 23, to 1258 AM October 24, 2001.

From about 930 pm CDT, Tuesday October 23, 2001 through about 100 am CDT, Wednesday, October 24, 2001, several clusters of severe thunderstorms bombarded parts of south-central and southeast Wisconsin with hailstones 1.00 to 3.00 inches in diameter. The counties of Green, Rock, Walworth, and Racine experienced the largest hailstones, and locally heavy rains of 1 to 3 inches.

The most intense fall of hail occurred in the southern parts of the city of Racine where 2 to 3 inch diameter hail accumulated to an initial depth of about 6 inches. The combination of leaves and hail quickly blocked sewers, resulting in backed-up water in streets and flooding. The flood waters then concentrated and pushed hailstones in low spots until the hail depth reached 1 to 2 feet! At daybreak, City and Highway crews had to plow some of the roads in the area just north of Highway 11, from Pritchard Park east to Highway 32. Many vehicles and homes sustained hail damage.

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Racine resident, Diana Tobias, seen in photo to the right, mentioned that the fall of hail lasted about 10 to 15 minutes. Her husband used his snowblower to clear their driveway! She also mentioned that the water depth in the flooded street reach almost up to the waist of one person!

Elsewhere in the other affected counties, 1.00 to 2.00 inch hail was reported by law enforcement officials, amateur radio operators, and other storm chasers in the cities of Browntown, Brodhead, Orfordville, Afton, Janesville, Avalon, 5 NNW Darien, and of course, Racine.

NWS Doppler Radar rainfall estimates showed a swath of 1 to 3 inch amounts from around Browntown to Broadhead to Janesville to Elkhorn to Burlington to the southern part of the city of Racine.

Meteorologists use the term "elevated convection" when referring to the thunderstorms that affected southern Wisconsin overnight on October 23rd. In these situations, thunderstorms do not feed off of warm, moist air near the ground as they do during the summer season, but rather, they ingest warm, moist air found between 5000 and 10000 feet above the ground. During the overnight hours of October 23rd, relatively cool air was found in the lower atmosphere up to about 5000 above the ground, with the warm, moist air above.

There have been a couple other "elevated convection" episodes to affect Wisconsin with large hailstones in the past few years. One such complex tore through central Wisconsin during the morning hours of May 12, 2000, leaving behind $121.6 million in damage brought on by hailstones 1 to 3 inches in diameter driven by straight-line winds of 50 to 100 mph.